1. Field of the Invention
This invention relates generally to systems and methods that facilitate medical diagnosis and treatment of patients with compromised coagulation function that results in bleeding or, conversely, overactive coagulation that results in abnormal blood clotting or thrombosis.
2. Description of Related Art
It is well known in the art to inhibit the coagulation of a patient's blood by administering various anticoagulant substances, such as, for example, heparin, to the blood, which compromises the patient's blood coagulation function (i.e., causes iatrogenic coagulopathy). Inhibiting the coagulation of blood in a patient is particularly useful during medical procedures which may, for example, utilize extracorporeal circulation, such as medical procedures including cardiopulmonary bypass for cardiovascular surgery, extracorporeal membrane oxygenation (ECMO), cardiac assist devices such as artificial hearts or intra-aortic balloon pumps, and hemodialysis. After the medical procedure requiring compromised coagulation function is completed, it is then often desirable to restore coagulation function in the blood of the patient. Again, it is well known in the art to restore coagulation function in the blood of a patient having compromised coagulation function by administering known agents, such as, for example, protamine or heparinase, that counteract the anticoagulant substance.
Systems and methods for testing the impact or effectiveness of anticoagulant and/or coagulant reagents are known. These systems perform tests that individually are generally very narrow, testing only one aspect of coagulation, and requiring very few reagents to be mixed with a patient's blood. These systems further require an operator to place bottles of reagents into automated analyzers (which then pipette reagents from the bottles into the patient blood or plasma samples) or to manually add reagents to the patient sample, as for example when an operator manually pipettes reagents into plasma, followed by manual placement in—a platelet aggregometer. Whether an automated pipette is used, or an operator manually uses a pipette, to introduce the coagulation affecting reagents, such reagents are serially provided, one after another. Regardless whether each reagent is obtained from a large, multi-dose vial/bottle or from a tube pack, the operator is still required to manually manipulate the reagents and deliver the reagents to the system reservoirs individually. In addition, because reagents can be supplied in varying forms and temperatures, e.g., frozen, refrigerated, native and lyophilized (requiring re-hydration and mixing and/or warming), the time required for the operator to prepare the reagents and deliver them to the reservoirs may be significant.
Additionally, such known systems are designed for fast throughput, namely, providing one large bottle of reagent for many patients so that many tests can be done rapidly. Since reagents are expensive, and large bottles have a very short shelf life once opened, hospitals frequently choose not to perform coagulation testing, or choose only to perform certain tests on limited days (holding samples sent to the lab for several days to batch them together) to ensure a larger number of patient samples in need of testing, so as not to waste reagents. Furthermore, hematology devices are sometimes built with refrigerated platforms for holding the large bottles of reagents to help prevent spoilage.
Furthermore, whenever a human element is introduced into any system, a chance for human error follows. The chance for error only increases as the number of tests, and the number of coagulation affecting reagents used per test, increases. With such systems and methods, there is a risk that an operator particularly under the stresses of an operating room environment, or the productivity requirements of a central laboratory, may not fill the reservoirs with the correct type, concentration or amount of reagent, and may thereby jeopardize the test results.
Thus, a need exists for an improved method and system for testing coagulation and/or anticoagulation substances and, more specifically, of delivering multiple such substances for testing with a patient's blood.